【模板】滑动窗口

import java.util.*;

import java.io.*;
// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader bf=new BufferedReader(new InputStreamReader(System.in));
        String[] lineone=bf.readLine().split(" ");
        String[] linetwo=bf.readLine().split(" ");
        int n=Integer.parseInt(lineone[0]),k=Integer.parseInt(lineone[1]);
        int[] arr=Arrays.stream(linetwo).mapToInt(Integer::parseInt).toArray();
        Deque<Integer> dq=new LinkedList<>();//维护单调队列
        StringJoiner sj=new StringJoiner(" ");

        for(int i=0;i<n;i++){
            //单调递减
            while(!dq.isEmpty()&&arr[dq.peekLast()]<=arr[i]){
                dq.pollLast();//队尾安全出队
            }
            dq.offerLast(i);

            //如果队首划过窗口则移除
            if(dq.peekFirst()<=i-k){
                dq.pollFirst();
            }

            //够窗口大小时收集元素
            if(i>=k-1){
                sj.add(arr[dq.peekFirst()]+"");
            }
        }
        System.out.println(sj.toString());
        
    }
}